/* * Copyright (C) 2003-2011 The Music Player Daemon Project * http://www.musicpd.org * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ #include "config.h" #include "ape.h" #include <glib.h> #include <stdint.h> #include <assert.h> #include <stdio.h> #include <string.h> struct ape_footer { unsigned char id[8]; uint32_t version; uint32_t length; uint32_t count; unsigned char flags[4]; unsigned char reserved[8]; }; static bool ape_scan_internal(FILE *fp, tag_ape_callback_t callback, void *ctx) { /* determine if file has an apeV2 tag */ struct ape_footer footer; if (fseek(fp, -(long)sizeof(footer), SEEK_END) || fread(&footer, 1, sizeof(footer), fp) != sizeof(footer) || memcmp(footer.id, "APETAGEX", sizeof(footer.id)) != 0 || GUINT32_FROM_LE(footer.version) != 2000) return false; /* find beginning of ape tag */ size_t remaining = GUINT32_FROM_LE(footer.length); if (remaining <= sizeof(footer) + 10 || /* refuse to load more than one megabyte of tag data */ remaining > 1024 * 1024 || fseek(fp, -(long)remaining, SEEK_END)) return false; /* read tag into buffer */ remaining -= sizeof(footer); assert(remaining > 10); char *buffer = g_malloc(remaining); if (fread(buffer, 1, remaining, fp) != remaining) { g_free(buffer); return false; } /* read tags */ unsigned n = GUINT32_FROM_LE(footer.count); const char *p = buffer; while (n-- && remaining > 10) { size_t size = GUINT32_FROM_LE(*(const uint32_t *)p); p += 4; remaining -= 4; unsigned long flags = GUINT32_FROM_LE(*(const uint32_t *)p); p += 4; remaining -= 4; /* get the key */ const char *key = p; while (remaining > size && *p != '\0') { p++; remaining--; } p++; remaining--; /* get the value */ if (remaining < size) break; if (!callback(flags, key, p, size, ctx)) break; p += size; remaining -= size; } g_free(buffer); return true; } bool tag_ape_scan(const char *path_fs, tag_ape_callback_t callback, void *ctx) { FILE *fp; fp = fopen(path_fs, "rb"); if (fp == NULL) return false; bool success = ape_scan_internal(fp, callback, ctx); fclose(fp); return success; }